The present invention relates to a conduit repairing material, a repairing structure and a repairing method using the same, and particularly relates to a repairing material for repairing degraded existing conduits such as sewer pipes, storm water pipes, and tunnels for various transportation modes, a repairing structure constructed by laying the repairing material, and a repairing method for installing the repairing material in an existing conduit.
When an existing conduit such as a sewer pipe, a storm water pipe, and a tunnel for various transportation modes is deteriorated, its repair is required depending on the degree of deterioration. When the deterioration of a conduit is minor, it is possible to repair it by applying mortar or other materials partly on the surface. However, when the deterioration is severe or widespread, the whole of a deteriorated conduit needs to be repaired with a repairing material.
Especially for repairing an existing conduit with a large diameter, it is effective to repair the entire conduit with a repairing material; and therefore such a repairing material and a repairing method for repairing an entire conduit are desired.
So far, several methods for repairing existing conduits such as a large diameter sewer pipe have been known.
For example, JP, A,8-277992 discloses a repairing method comprising: preparing a resilient reinforcing steel such as piano wire to be wound in a spiral form along the inner surface of an existing conduit, forming a tubular liner by winding a strip-like plastic plate over the reinforcing steel, and injecting a curable infilling (grouting material) such as mortar between the liner and the inner surface of the existing conduit. In this method, however, the reinforcing steel such as piano wire is not engaged with the plastic plate, and therefore the plastic plate itself is not reinforced. Therefore, when it is applied to repairing of a buried pipe, the curable infilling such as a mortar layer would be subject to cracks caused by vibrations due to vehicle passage or earthquakes. Thus, underground water will permeate through the cracks thereby directly applying water pressure against the plastic plate, and this may cause the plastic plate to bulge into the conduit at positions where the adhesion strength between the curable infilling such as mortar and the plastic plate is insufficient.
JP, A, 10-166444 discloses a repairing method which comprises: preparing a resilient strip-like plastic plate, which is to be formed into a liner by spirally winding it in an existing conduit, to bring it into engagement with a long reinforcing body containing a reinforcing steel, forming a liner by spirally winding the plastic plate along the inner surface of the existing conduit, and injecting a grouting material such as mortar between the liner and the inner surface of the existing conduit. In this method, although the plastic plate is reinforced by being integrated with a reinforcing body containing reinforcing steel in advance, it is not possible to employ a reinforcing body having a sufficient rigidity because the plastic plate needs to be spirally wound in the existing conduit. Therefore, when the existing conduit does not have enough strength, the reinforcement against the earth loads will not be sufficient.
In each of the above described conventional repairing methods for existing conduits, a reinforcing steel is utilized to raise the strength of the conduit after it is repaired; however, it is hardly assured that the plastic plate be reinforced to a sufficient level. Furthermore, when injecting mortar or the like between the existing conduit and the liner, it is necessary to place a supporting on the inner surface of the liner or to perform grouting with mortar or the like in several split operations adding one after another to prevent the deformation of the spirally wound plastic plate due to the pressure of the injection. And this would make the execution of the laying operation complex and time consuming.
On one hand, conventionally, there is known a construction method in which a lining material is laid along the inner surface of an existing conduit, and a grouting material such as mortar and cement milk is injected into a gap between the lining material and the inner surface of the existing conduit to be cured.
This type of construction methods, as disclosed, for example, in JP, A, 63-88388, typically utilizes a repairing method which comprises: preparing an injection hose to be inserted into a tubular gap formed between the inner surface of an existing conduit and the lining material, filling the opening parts of the tubular gap at its both ends in the lengthwise direction with mortar for sealing, and in that state, injecting a grouting material into the tubular gap through the injection hose.
However, in the conventional method in which a grouting material is injected in a state that the opening parts at both ends of the gap between the inner surface of an existing conduit and the lining material are sealed up with mortar, it was impossible to start injecting the grouting material until the sealing mortar is cured, and also it was required to conduct the injection of the grouting material at a low pressure since the sealing by the mortar may be destroyed due to the pressure during the injection of the grouting material. Moreover, when water is flowing inside the existing conduit, it is difficult to apply complete sealing with mortar, and thus the grouting material may flow out through part of the sealing. For these reasons, the conventional construction method in which both ends of the gap are sealed up with mortar had a problem in that the operation of injecting the grouting material is inefficient and time consuming.
In order to solve the above described problems, it is an object of the present invention to provide a repairing method for an existing conduit, in which the inner face bar such as a plastic plate forming the inner surface of the repaired conduit will not be directly subject to exterior water pressure, the existing conduit will be reinforced even when it has a low strength, and repairing work can be easily carried out without need of counter measures such as placing a supporting when injecting a curable infilling (grouting material) such as mortar, and also to provide a repairing material to be used for the method and the repairing structure obtained by the repairing method.
It is another object of the present invention to provide a grouting structure for the end parts of a repairing material for a conduit, whereby the end parts of the gap into which the grouting material is injected can be securely sealed up without being affected by the surface conditions of the existing conduit such as running water, the injection of the grouting material can be performed stably at a high pressure, and moreover a high quality of the grouting material after curing can be secured.
To achieve the above described objective, the present invention provides a repairing method for an existing conduit, characterized by comprising: preparing a plurality of reinforcing members capable of being carried into the existing conduit, assembling the reinforcing members into a hollow skeleton-like reinforcing body extending substantially along the inner surface of the existing conduit, attaching a plurality of inner face bars to the inside of the reinforcing body to assemble then into a tubular form along the length of the existing conduit, and thereafter injecting a curable infilling into a gap between the inner face bar and the inner surface of the existing conduit.
In the repairing method for an existing conduit according to the present invention, it is possible to adopt a method in which a plurality of fixing bars are attached to the inside of the above described reinforcing body, and the above described inner face bars are fitted into the fixing bars. When using such fixing bars to attach the inner face bars onto the reinforcing body, the fixing bar is preferably a long member continuous along the lengthwise direction of the existing conduit.
Also, in the repairing method for an existing conduit according to the present invention, the above described inner face bar is preferably a long body continuous in the lengthwise direction of the existing conduit.
In the repairing method for an existing conduit according to the present invention, it is possible to suitably adopt a method in which a plurality of ring-like reinforcing members extending substantially along the inner periphery of the existing conduit are placed at a predetermined interval in the lengthwise direction to be assembled, and then each ring-like reinforcing member is integrated with each other in the length wise direction of the existing conduit by use of connecting members.
Moreover, in the repairing method for an existing conduit according to the present invention, it is possible to suitably adopt a method in which circumferentially divided parts of the ring-like reinforcing member are assembled together outside the existing conduit by means of connecting members into partial reinforcing bodies and thereafter the partial reinforcing bodies are carried into the existing conduit to be assembled into the reinforcing body.
Furthermore, in the method of the present invention, it is preferable to provide a space-infilling on the outer periphery of the reinforcing body so that the gap between the inner peripheral surface of the existing conduit and the reinforcing body will be reduced or eliminated.
Also, in the method of the present invention, it is possible to adopt a method in which the above described reinforcing body is assembled after a tubular surface bar extending along the inner surface of the existing conduit is placed on the inner surface of the existing conduit.
Moreover, in the method of the present invention, the injection of curable infilling may be conducted from an injection opening for grouting material formed in the permeable material that is provided near the end parts of the repairing material.
It is preferable to inject a curable infilling using an end structure of the repairing material to be described later for injecting the grouting material into the gap formed between the inner surface of the existing conduit and the repairing material laid inside the conduit.
On one hand, the repairing material for an existing conduit according to the invention is a repairing material suitable for use in the above described repairing method of the present invention. According to its one embodiment, the repairing material is characterized by comprising: a reinforcing body having a hollow skeleton structure extending substantially along the inner surface of the existing conduit, the reinforcing body being assembled from a plurality of circumferentially divided ring-like reinforcing members each of which is provided in its inside with a plurality of fixing parts, and a plurality of inner face bars having a smooth surface to form the inner surface of the conduit.
Also, according to another embodiment, the repairing material of the present invention is characterized by comprising: a reinforcing body having a hollow skeleton structure extending substantially along the inner surface of the existing conduit, the reinforcing body being assembled from a plurality of circumferentially divided ring-like reinforcing members each of which is provided in its inside with a plurality of fixing parts; a plurality of fixing bars which is formed in its outside with a first fixing part to fit into the fixing part and in its inside with a second fixing part; and a plurality of inner face bars having a smooth inner surface and formed in its outer surface or end part with a fixing part to fit into the above described second fixing part. When using such a fixing bar, it is preferable that each fixing bar is configured to be a long member continuous in the lengthwise direction of the existing conduit.
It is also preferable that the inner face bar used in the repairing material for existing conduits according to the present invention is configured to be a long body continuous in the direction of the existing conduit.
Moreover, in the repairing material of the present invention, it is more preferable that the reinforcing body is provided with a plurality of connecting members to connect and integrate ring-like reinforcing members extending substantially along the inner periphery of the existing conduit and to dispose them at a predetermined spacing in the lengthwise direction of the existing conduit.
Furthermore, in the repairing material of the present invention, the reinforcing body is preferably provided in its outer periphery with concavities and convexities to form groove-like gaps at least continuous in the lengthwise direction of the existing conduit, and in stead of or in addition to this, the reinforcing body is preferably formed with a through hole passing in the lengthwise direction of the existing conduit.
Furthermore, in the repairing material of the present invention, the reinforcing may comprise a space-infilling which can be fixed to its outer peripheral, and which thereby can reduce or eliminate the gap between the reinforcing body and the inner surface of the existing conduit.
The repairing structure for a conduit according to the present invention provides a repairing structure to be obtained by using the repairing method for an existing conduit according the present invention and characterized in that: a hollow skeleton structure extending substantially along the inner surface of the existing conduit is disposed in the existing conduit; a plurality of inner face bars continuous in the lengthwise direction of the existing conduit are attached to the inside of the above described reinforcing body, with the inner face bars being disposed like a tubular form extending along the lengthwise direction of the existing conduit; and a curable infilling is provided to fill in between the inner face bars and the inner surface of the existing conduit.
Moreover, in the repairing structure for an existing conduit according to the present invention, the inner face bars may be attached to the reinforcing body via a plurality of fixing bars mounted onto the inside of the reinforcing body. When using such a fixing bar, the fixing bar is preferably configured to be a long member continuous in the lengthwise direction of the existing conduit.
Furthermore, in the repairing structure for conduits according to the present invention, the reinforcing body is preferably configured to comprise a plurality of ring-like reinforcing members extending substantially along the inner surface of the existing conduit, and a plurality of connecting members for connecting and integrating each ring-like reinforcing member in the lengthwise direction of the existing member.
Also in the repairing structure of the present invention, it is possible to suitably adopt a structure in which the reinforcing body is formed with a through hole passing in the lengthwise direction of the existing conduit, and the hole is filled with a curable infilling.
Furthermore, in the repairing structure of the present invention, it is possible to adopt a structure in which a tubular surface bar extending along the inner surface of the existing conduit is interposed between the reinforcing body and the inner surface of the existing conduit.
The present invention is intended to achieve the intended object by a configuration in which the inner face bars, which form the surface (inner surface) of the conduit after repairing, are attached onto the reinforcing body assembled into a hollow skeleton structure extending substantially along the inner surface of the existing conduit so that the reinforcing body has sufficient strength to receive the force acting on the inner face bar.
In the present invention, there is no limitation on the means for attaching the inner face bar to the reinforcing body; fitting using a concavity and convexity provided on both members, or fitting via a fixing bar, or means such as fastening by screws can be adopted.
In the repairing method for existing conduits according to the present invention and the repairing material for use in the repairing method, divided reinforcing members are assembled into a reinforcing body having a hollow skeleton structure extending substantially along the inner surface of the existing conduit, and this makes it possible to change the shape and size of the reinforcing body depending on the condition of the existing conduit and construct a reinforcing body with sufficient strength within the existing conduit corresponding to the degree of the degradation of the conduit, and also to securely reinforce an existing conduit even when it has lost strength. Thus, the repaired conduit will have strength equal to that of a steel-reinforced structure.
In the method of the present invention in which reinforcing members are assembled to form a hollow skeleton-like reinforcing body, it is possible to easily cope with special-shape conduits such as a horseshoe-shape conduit. At the same time, as a result of obtaining sufficient strength of the reinforcing body, it becomes possible to choose a material of a good fluidity and of a low cost such as mortar with a low water content and air mortar thereby providing a method of low cost and enhanced workability.
Also, according to the present invention, since the inner face bars are attached to and supported by the reinforcing body, water pressure from outside will not be applied directly to the inner face bar and there is no need for counter measures against the injection of curable infilling such as constructing a supporting and performing additional injections, thereby making the installation to be performed easily in a short time.
Moreover, in another embodiment, adopting a structure in which the inner face bars are attached to the reinforcing body via fixing bars makes it possible to give margin in the dimensional precision of the fixing part between the reinforcing body and the inner face bar, compared to the case in which the inner face bar is directly fixed to the reinforcing body which is embodied as a rigid body. And this would improve the workability and increase the freedom of choosing the material of the inner face bar in accordance with the required functions for the conduit, for example, exploiting a thermoplastic resin molded part as the fixing bar making it possible to use a rigid body for the inner face bar, thus providing the repairing materials with additional functions such as flame retardancy.
Moreover, when using such a fixing bar, exploiting a plurality of fixing bars continuous in the lengthwise direction of the existing conduit to construct a repairing structure for conduits according to the present invention makes it possible to construct a structure in which the inner face bars, which are to be attached to a plurality of reinforcing members of the reinforcing body, are reinforced. This structure can prevent the deformation of the inner face bar thereby allowing the use of thinner inner face bar. Also using fixing bars of a length extending between adjacent manholes offers an advantage that a seamless watertight structure can easily be achieved.
Moreover, in another embodiment in which the inner face bar is configured to be a long member continuous in the lengthwise direction of the existing conduit and a plurality of long members are assembled into a tubular form to construct a conduit repairing structure of the present invention, it is possible to achieve a conduit which is seamless in the lengthwise direction thus substantially increasing the flow capacity of the conduit. In such cases, inner face bars of a similar seize and shape with those used for the cylindrical conduit can be applied to special-shape conduits such as a horseshoe-shape conduit, a box culvert (rectangular conduit), or tunnels of various sectional shapes since the inner face bar is divided into a plurality of members in the circumferential direction of the existing conduit. Therefore, the inner face bars can easily be disposed depending on the sectional shape of a conduit thus improving workability.
Furthermore, in another embodiment, by configuring the reinforcing body such that a plurality of ring-like reinforcing members extending substantially along the inner periphery of the existing conduit are disposed at a predetermined interval in the lengthwise direction of the existing conduit, it is made possible to construct a conduit capable of resisting the increase of the exterior pressure. Also, by connecting and integrating the ring-like reinforcing members by means of connecting members to construct the conduit repairing structure of the present invention, a configuration in which a core is formed in the existing conduit is obtained thus significantly enhancing the structural strength of the conduit. Moreover, by adjusting the length of the connecting members between the ring-like reinforcing members so that the shape of the gap between the ring-like reinforcing members is a reversed V-shape, it is possible to cope with a bend of the existing conduit. Also by forming a reversed V-shape and a V-shape, it is possible to cope with a step in the conduit.
In another embodiment, it is possible to adopt a technique which utilizes the above described connecting members and comprises: circumferentially dividing a ring-like reinforcing member into three parts, assembling a partial reinforcing body, which is circumferentially divided into three parts and has a length capable of being easily carried into an existing conduit, from the divided parts and the connecting members outside the conduit, and carrying the partial reinforcing bodies into the conduit for assembly. This technique would make it possible to reduce the assembly time and, when applied to special-shape conduits, also improve workability since the sections which are difficult to assemble such as a corner section can be assembled outside the conduit.
In another embodiment, by reducing or eliminating the gap between the reinforcing body and the inner surface of the existing conduit with a space-infilling, it is made possible to prevent the reinforcing body from floating up due to the buoyant during the injection of the curable infilling by attaching the space-infilling on the top of the reinforcing body. Also attaching the space-infilling onto the side portion of the reinforcing body acts to restrict the vertical displacement of the reinforcing body by pressing itself against the inner surface of the existing conduit, thereby making the reinforcing body insusceptible to deformation.
In another embodiment, by disposing a tubular surface bar in an existing conduit in advance, it is made possible to prevent the curable infilling from flowing out of the conduit even when the damage of the existing conduit is severe, and also prevent the contact with underground water. Therefore, the properties of the curable infilling such as mortar will not deteriorate due to a situation of an existing conduit. Also by using a permeable material for the surface bar and a cement material including mortar for the curable infilling, it is made possible to discharge excessive water and air induced during the injection of the curable infilling out of the surface bar by filtration effect. Consequently, the cement material inside the surface bar becomes a compacted state and therefore insusceptible to underground water even before it is cured completely, thus ensuring high strength after curing.
Moreover, in another embodiment, by providing in the outer periphery of the reinforcing body with concavities and convexities continuous at least in the lengthwise direction of the existing conduit, a continuous gap is formed between the inner surface of the existing conduit and the reinforcing body, and thus it is made possible to reduce the resistance against the injection of a curable infilling such as mortar. Such formation of concavities and convexities is also effective in weight reducing of the reinforcing body.
Furthermore, in another embodiment, providing the reinforcing body with through holes in the lengthwise direction of the conduit is also effective in reducing the resistance against the injection of curable infilling as with the case described above and also in reducing the weight of the reinforcing body. Also by adopting such a reinforcing body to construct a repairing structure of the present invention, it is made possible to enhance the boding strength between the curable infilling and the reinforcing body through an anchor effect produced by the curable infilling cured in the reinforcing body and through holes thereof.
On one hand, configuring the inner face bar to be continuous in the lengthwise direction brings about an advantage that there are no seams in the lengthwise direction of the existing conduit thereby increasing the flow capacity of the conduit. Also configuring the fixing bar for securing the inner face bars onto the reinforcing body to be continuous in the lengthwise direction of the existing conduit has an advantage that the mounting strength of the inner face bars onto the reinforcing body is increased. But, in some situations where the repairing length of the existing conduit is increased, using the inner face bar and the fixing bar which are continuous in the lengthwise direction of the existing conduit will cause a problem in their transportation and manufacturing facilities. That is, upon manufacturing, typically the inner face bar or the fixing bar is taken up on a reel, but when their lengths exceed a certain limit, the diameter of the drum or reel will become too large after taking up them, thus causing problems such as storage spaces in the manufacturing site. Also, transporting these drums or reels will need a large vehicle that has difficulty in running on the ordinary driving lanes.
In such cases, the present invention provides a repairing structure for existing conduits which can solve the above described problems of manufacturing facilities and transportation while maintaining an equal effect as in the case of utilizing the inner face bars or fixing bars continuous in the lengthwise direction.
That is, a repairing structure for an existing conduit according to the present invention is characterized in that: a hollow skeleton-like reinforcing body extending substantially along the inner surface of the existing conduit is disposed in the existing conduit; a plurality of inner face bars are attached to the inside of the reinforcing body successively in the circumferential direction and the lengthwise direction of the existing conduit respectively to be assembled into a tubular form; the inner face bars adjoining to each other in the lengthwise direction are connected with their end faces being abutted against each other by means of an inner face bar connecting member which is placed over both of the adjoining inner face bars; and a curable infilling is provided to fill in between the inner face bar and the inner surface of the existing conduit.
In the present invention, it is possible to adopt a structure in which a plurality of fixing bars are attached to the inside of the reinforcing body in the lengthwise direction and the circumferential direction respectively, the above described inner face bars are attached to the reinforcing body via each of the fixing bars, and fixing bars adjoining to each other in the lengthwise direction of the existing conduit are connected together with their end faces being abutted against each other with a fixing bar connecting member which is placed over both fixing bars.
Also, in the present invention, it is possible to adopt a structure in which the above described inner face bar connecting members for connecting the inner face bars are arranged such that two of circumferentially adjacent members are displaced from each other in the lengthwise direction of the existing conduit.
Moreover, in the present invention, it is possible to adopt a structure in which the above described fixing bar connecting members for connecting the fixing bars adjoining to each other in the lengthwise direction of the existing conduit are arranged such that two of the circumferentially adjacent members are displaced from each other in the lengthwise direction of the existing conduit.
Furthermore, in the present invention, it is possible to adopt a structure in which the above described inner face bar connecting members and the fixing bar connecting members are displaced from each other.
Furthermore, in the present invention, it is possible to adopt a structure in which end faces of the above described inner face bars and/or fixing bars adjoining to each other in the lengthwise direction are integrated together by bonding.
Furthermore, in the present invention, it is preferable to adopt a structure in which a sealing material is interposed between the above described fixing bar and the inner face bar.
The present invention is addressed to achieve an intended purpose not by configuring the inner face bars to be continuous over the whole repairing length of the existing conduit as previously proposed, wherein the inner face bars are attached to the reinforcing body provided inside the existing conduit to be assembled into a tubular form as a whole, but by dividing the inner face bars into a plurality of parts in the lengthwise direction of the existing conduit and firmly connecting them together with their end faces abutted against each other.
That is, in one embodiment of the present invention, an inner face bar is divided into a plurality of members and end faces of these members are abutted to each other to connect them together by means of inner face bar connecting members which are disposed spanning over two adjacent members, thus raising the connection strength. In this configuration, the connected portion will not be deformed during the injection of a curable infilling or due to external (water) pressure or internal (water) pressure, and thus a reinforcing effect comparative to that of a single long member is achieved. Thus, it is made possible to use standard size members for the inner face bar, thereby solving the problems in manufacturing and transportation caused by longer members, and the ease of handling is also improved thus improving the workability in the field.
Similarly, a fixing bar is also divided into a plurality of members and end faces of these members are abutted against each other and connected together with fixing bar connecting members which are disposed over tow adjacent members. This configuration provides a reinforcing effect comparative to that of a single fixing bar, thus solving the problems with manufacturing and transportation as described above and, at the same time, provides the ease of handling thereby improving the workability in the field.
And, in another embodiment of the present invention, the positions at which the inner face bars are connected in the lengthwise direction with inner face bar connecting members are displaced for circumferentially adjacent ones so that the connecting positions of the inner face bars are not continuous in the circumferential direction. This offers an advantage that when a gap is produced in a connected portion of the inner face bars due to a tension on the repairing material in the lengthwise direction caused by, for example, an earthquake, the gap will not grow continuously in the circumferential direction and therefore the curable infilling will be resistant to fractures.
Also, in another embodiment, the positions at which the fixing bars are connected in the lengthwise direction with fixing members connecting member are displaced in the lengthwise direction for circumferentially adjacent pairs so that even when a gap is produced in a connected portion due to a tension applied on the repairing material in the lengthwise direction. This configuration provides an advantage that the curable infilling is insusceptible to cracks since the gap will not grow continuously in the circumferential direction.
Furthermore, in another embodiment, the inner face bar connecting members and the fixing bar connecting members are displaced from each other in the lengthwise direction so that either one of the connecting members exists circumferentially over the whole length of the conduit. This configuration makes it possible to enhance the effects of the present invention and prevent the curable infilling from flowing out onto the surface of the inner face bar during the injection of the curable infilling. Also, after the repairing material is formed, it is possible to prevent the fluid incoming from the inside and outside of the existing conduit flowing into or out of the inner face bar.
Furthermore, in another embodiment, the inner face bars and fixing bars, or the inner face bars or fixing bars are configured such that each portion in which end faces of adjacent members are abutted against each other is integrated by bonding, for example, with an adhesive or sealant. This configuration ensures the watertightness and connectivity of the connected portions of the inner face bars and/or fixing bars, thus further enhancing the above described effects.
Also by interposing a sealing material between the fixing bar and the inner face bar, it is possible to form a watertight structure between the inner face bar and the fixing bar. And particularly by adopting, at the same time, a configuration in which the positions of the inner face bar connecting members and the fixing bar connecting members are displaced from each other so that each inner face bar will be fitted into each fixing bar via a continuous sealing material at the connected portion of the inner face bar, it is made possible to secure a watertight structure at the connected portions of the inner face bars.
The grouting structure at an end part of the conduit repairing material of the present invention provides an end structure of the repairing material for injecting a grouting material into the gap formed between the inner surface of the existing conduit and the repairing material laid inside the conduit, characterized in that both ends of a tubular member made of a permeable material are fixed by pressure with a corresponding hollow diametrically-expansible member respectively to the inner surface of the longitudinal end part of the repairing material and the inner surface of the existing conduit at a position a predetermined distance outwardly away from the foregoing end part in the lengthwise direction, and that an injection opening for grouting material is provided in a near end part of the repairing material or in the above described tubular member.
In the present invention, it is preferable to adopt a structure in which a hollow resilient member is inserted either between both ends of the tubular member provided in the other end of the above described repairing material and the inner surface of the existing conduit or the repairing material, or between both ends of the tubular member and each hollow diametrically-expansible member.
The present invention is addressed to achieve an intended purpose by providing a structure in which the ends of the tubular gap formed between the existing conduit and the repairing material are sealed by fixing both ends of the tubular member made of a permeable material by pressure onto the inner surface of the existing conduit and the inner surface of the end part of the repairing material, instead of sealing up with a curable material such as mortar.
Thus, in the present invention, both ends of a tubular member made of a permeable material such as sailcloth made of textile such as woven fabric are fixed by pressure by means of a hollow diametrically-expansible member respectively onto the inner surface of the longitudinal end part of the repairing material and the inner surface of the existing conduit at a certain distance away from the foregoing end part outwardly in the lengthwise direction so that the tubular gap formed between the existing conduit and the repairing material is sealed up and a grouting material is injected through an injection opening provided in the inner surface of the repairing material near the sealed portion, or in the tubular member.
Accordingly, there will be no need for waiting until the curing is completed as in the case in which a curable material such as mortar is used for the sealing, and it is possible to start the injection of the grouting material right after applying sealing by means of the tubular member and to ensure stable sealing without being affected by the conditions of the inner surface of the existing conduit such as the existence of running water.
Moreover, by securely fixing each end of the tubular member by pressure to the inner surfaces of the existing conduit and the repairing material by use of a hollow diametrically-expansible member, it is also made possible to raise the injection pressure without leakage of grouting material through the sealing even in a high injection pressure and thereby reduce the time needed for the operation.
Moreover, the use of a tubular member made of a permeable material as the member for sealing makes it possible to discharge through the sealed portion excessive water and water incoming from the outside during the injection of the grouting material and prevent the formation of standing air. Thus the quality of the grouting material after injection is improved.
In the present invention, by placing a hollow resilient member on the outer periphery or inner periphery of each end of the tubular member instead of simply fixing by pressure each end of the tubular member onto the inner surface of the existing conduit and the inner surface of the repairing material, it is made possible to easily ensure the sealing at the portions of the tubular members fixed by pressure since the resilient member deforms conforming with the inner surfaces of the existing conduit and the repairing material even when there are concavities and convexities thereon. Thus, improvement of workability and upgrading of the injection pressure of the grouting material can be achieved.
Moreover, in another embodiment, it is possible to construct a structure in which, on one end of the repairing material, a grouting structure of the present invention described above is provided, and on the other end, another structure similar to the above described structure is provided in which each end of the tubular member made of a permeable material is fixed by pressure onto the inner surface of the end part of the repairing material and the inner surface of the existing conduit at a predetermined distance away therefrom in the lengthwise direction by use of a hollow diametrically-expansible member respectively. This structure makes it possible to discharge excessive water in the whole length of the injected grouting material and water intruded from outside, and to prevent the formation of standing air thus substantially improving the quality of the grouting material after injection.
Moreover, in the seal up structure on the above described end, by placing a hollow resilient member on the outer periphery or the inner periphery of each end of the tubular member, it is made possible to easily improve the sealing of the portion fixed by pressure, in which the tubular member is fixed by pressure onto the inner surface of the existing conduit and the inner surface of the repairing material by use of a hollow diametrically-expansible member, thus achieving the improvement of workability and further upgrading of the injection pressure of the grouting material.